1. Field of the Invention (Technical Field)
The present invention relates generally to the field of avionics for obstacle avoidance systems to provide complete coverage for both air collision avoidance and ground collision avoidance situations. More specifically, the present invention relates to a hybridized multiple domain handler avoidance system for managing instantaneous real-time feedback of obstacle data to provide a fully compatible obstacle solution to air and ground situation in a free flight regime.
2. Background Art
An aircraft equipped with an embedded free flight obstacle avoidance system (OAS) has the capabilities to uniquely avoid both a ground collision and an air collision. These capabilities are achieved by incorporating a dispatcher and collision resolver module. This module provides filtering of collision solution data, evaluating, and routing feedback data resulting from cross-domain verification in hybrid modules. By inserting hybrid processing capabilities, the hybrid ground collision avoidance module can predict if the solution produced by the hybrid air collision avoidance module will have a ground clearance and similarly, the hybrid air collision module can also predict if the solution produced by the hybrid ground collision module will not misguide the aircraft to an unsafe airspace.
Spurred by the collision of two airliners over the Grand Canyon in 1956, the airlines initiated a study of collision avoidance concepts. By the late 1980's, a system for airborne collision avoidance was developed with the cooperation of the airlines, the aviation industry, and the Federal Aviation Administration (FAA). The system, referred to as Traffic Alert and Collision Avoidance System II (TCAS II) was mandated by Congress to be installed on most commercial aircraft by the early 1990's. A chronology of the development of airborne collision avoidance systems can be found in “Introduction to TCAS II,” printed by the Federal Aviation Administration of the U.S. Department of Transportation, March 1990.
The development of an effective airborne obstacle collision avoidance system (CAS) has been the goal of the aviation community for many years. Airborne obstacle collision avoidance systems provide protection from collisions with other aircraft. As is well appreciated in the aviation industry, avoiding collisions with other aircraft is a very important endeavor. Furthermore, collision avoidance is a problem for both military and commercial aircraft alike. Therefore, to promote the safety of air travel, systems that avoid collision with other aircraft and terrain are highly desirable.
An air collision avoidance system (see, e.g., Tran, U.S. Pat. No. 6,262,697 B1, Midair Collision Avoidance System) monitors the flight paths of intruders operating in the same airspace with the aircraft to provide warnings and air collision avoidance commands. This system effectively provides solutions to air collision conditions and also provides solutions for potential terrain collision situations. Both of these systems are stand-alone systems. The prior art system does not describe a means to provide air collision feedback or provide a validation status for ground solutions from an air operational perspective. Lacking some of the refined capabilities of this invention, it is difficult for a “conventional” air collision avoidance system to provide a complete dynamics picture of air and ground situation along with the avoidance maneuvers or as herein referred to as obstacle avoidance.
Another prior art system is a ground collision avoidance system (see, e.g., Tran, U.S. Pat. No. 5,892,462, Adaptive Ground Collision Avoidance System), which uses a predictive flight path to estimate the flight path envelope along with the accurate terrain information to determine whether a ground collision condition exists. The resulting solution is determined from prediction calculations and provides warnings and appropriate generated maneuvers to avoid a ground collision. This solution is applied solely to a terrain elevation domain without taking the aircraft's traveling in time and in space into consideration. Without the feedback and validation of the solution from an air collision coverage domain, the avoidance solution in many instances does not have a complete free clearance for obstacle avoidance.